Feed cover-plates for sewing machines



Aug. 9, 1960 J. P. ENOS, 2,948,244

FEED COVER-PLATES FOR SEWING MACHINES Filed Feb. 15, 1955 Fig.3

INVENTOR John P Enos WITNESS MMWM BY A TTORNE Y 'ment in a novel manner. r

It is a further object of this inventionto'provide an .stantially alongv lines 3 3 of Fig. 2,;

l the for o scillation in timed relation was reciproc "tiontof the needle as iswell. known in. the r FEED covnktnmrns ronfsn'wme John P; Enos; Union, NE, assignor to facturing Company, Elizabeth; NiR- a "corporation of NewJersey :4 w

amail' iia a- 88 1 comm. cutie-26o w P tented Aug. a, teen 2 tures in a throat-plate 16 fitted in the cloth support 12 ofv the machineframe is a feed-dog 17 which, during normal operation of the sewing machine in theabsence of a feed cover-plate, serves to advance the work. past the stitch-forming instrumentalities to form a line of .s'titchesr Also carried in the bracket arm portion (not shown) of the .machine fratne is a Presser-bar to which is secured, as best illustrated-in Fig. l, a hemstitching attach.- mentflg provided with a forked. actuating lever 19 disposed to embrace a needle clamp 21 on the needle bar 14. "The hemstitching attachment is of the type diswork fabric-the: operatorr mayf produce a stitch: pattern beyond that obtainable with use .ofithe sewing machine 'Worlc-feeding mechanism; art as. when a. supplemental device is applied to the sewing'machine, snchas: a hemstitching attachment in. which all necessary feeding movements of the work fabric are imparted' by the: metas;

ment. a 1 I a It is anobject of. this invention to provide a feed 'cover plate which is formed in a novel mannerto ,co-

operate advantageously with" fabric shifting means other than those of the sewing machine.

A further object is to provide a feed cover-plate which is adapted to cooperate with' a hemstitchingattachment to enhance the etfectivenessof operation of the attachlattachment fastening device which may be readilyand closed, in the US. patent of Hinman et al. No. 2,069,652, Feb. 2, 1937, to which patent reference may be had for a detailed description thereof. For an understanding of the. present invention, it will be sufiicient to understand that .the hemstitching attachment includes a, presser member- 22 and a feeding member formed with spaced workengaging fingers 23-43 disposed one at each side of the presser member. The presser and feeding members of the attachment are alternately moved into engagement with the work fabric, the presser member serving to clamp the work inplace during stitching at which time the return stroke. of the feeding member occurs while .the work-engaging. fingers areraised clear of the, work.

Pattern. a

.g'roup of stitches may b made to form a hemstitch Sincethe remaining. attachment thus provides a complete mechanism forfeedingthe-work fabric; the

action of the-sewing machine feed-dog 17 becomesnot Ionly nnneces sary but undesirable. For the purposeof rendenng the feed-dog. ineiiective, a feed cover-plate,

I indicated generally as 26 is provided; 'The feed coverconveniently applied ordet ached from a sewing machine.

With the aboveand additional objects and advantages in view as will hereinafter appear,this-invention comparts hereinafter described and illustrated in'the accompanying drawings of 'a preferred embodiment in which:

Fig..'1 represents a head end elevational'view of a portion of'a sewing machine having a hemstitchin'g at- "p'fisesthe devices, combinations and. arrangements of tachment of well k nownv construction operativelyposi T t'i'oned thereon, and to which impmym f ed dv ei plate has been applied; t

.Fig. 2, represents a top plan". view of theffe'ed coverplate of. this invention including a portion of the sewing machine and indicates in dotrand dashed lines portions of the .hemstitching attachment oflFig. 1 and Fig. 3 represents a' cross-sectional yiew' taken -s'ub- Referring-more particularly to the drawings, the sewmg machine frame, isformed' witha bed 11 havingla flat isv carried by a bracket arm portionjn'ot shown) of the of stitches with. ashuttle 15 911 is jonrnaledbeneath an ting from beneath the bed upwardly through suitable aper- -.sewing machinef'rame, and cooperates inthe formation .plate} is. preferably formed with arim portion 27 adapted to -bear against the cloth supporting plate 12 and to l snstain. a raised ,flat feed cover portion 28 adapted to overlie .the sewing, machine throat-plate and feed-dog. .Thepressermember 22 and workrengaging fingers 23--23 thehemstitching attachment'are adapted to. bear upon ,the work supported on the raised sheetmetal'portion 28 of the feed cover-plate generally inthe positions shown m 'dot-and-dashed lines in :Fig. 2, the :raised feed cover portion 28 "being formed with apertures 29 and 30 to accommodate, respectively, the piercer 24 and the needle 13. f 1

Extending from the rim portion 27 is an arm 31 proyidedwitha channel 32 preferably in the form of an longated slot which is formed with sufficient clearance to admit freely the threaded. portion of a pair of cover- :which, until the presentinvention, has not been satisfac-' torily, solved. If ordinary fastening screws are used, they are certain tobecome lost or misplaced among the countless number of similarly small articles which invariably accumulate in'a sewing storage box. It has been known to form! a neck between the threaded portion of the "fastening screw and its head and thereby to maintain the screw captive'directly in an'el'ongated slot, such as the "channel 32 of arm 31.

This practice is theoretically satisfactory but proves to be particularly unsatisfactory practice because it' is undesirableowing to the thickhess of the bed-portion 1 2 to make the necked portion long enough to -permit eitheriof the screws to be tightened or removed in one operationQ- UnlesS-the screws are 3 tightened or loosened together, that is, by alternately turning each a fraction of a turn, the slotted arm will be tilted and possibly bent and the assembly will either bind tightly or the threads will be stripped.

The present invention not only solves the problem, but it also provides other novel advantages of convenience in use. The fastening screws 33, as best illustrated in Fig. 3, are each formed with a necked portion 35 between the threaded shank and an enlarged head'36. The fastening screws are held captive each at the extremity of a respective one of the resilient arms 3737 of a fastening screw retainer member 38. For this purpose, the free extremity of each resilient arm is formed with a keyhole-shaped slot 3939 which may be deformed to admit the necked portion 35 of a fastening screw. The screw retaining member 38 is formed with an elongated aperture 40 which is secured loosely by a rivet 41 to the arm 31 of the cover-plate 26 so that the fastening screws are permanently captive with respect to the feed cover-plate and cannot become lost or misplaced. The retainer member 38 maintains the fastening screws in a predetermined spaced relationship alongthe channel 32 in the arm 31corresponding to the space between tapped holes 34 formed in a conventional sewing machine cloth plate. Thus, when one of the screws 33 is aligned with one of the tapped holes, the other will also be properly aligned. The separate arms 37-37 of the screw retaining member are quite flexible and permit each of the fastening screws to be individually tightened or removed in turn, and alleviate completely the possibility of binding duringthe application or removal of the attachment to the machine.

During the course of stitch formation when the feed cover-plate 26 is being used, there are intervals during which the work fabric may be shifted. At other periods, however, it is of the utmost importance to high quality stitch formation that the work fabrics be held stationary and clamped securely in this position. Referring more particularly to the hemstitching attachment illustrated in the drawings, it is the function of the feeding fingers 23 to advance the fabrics with respect to the stitch-forming instrumentalities and, therefore, the feed cover-plate beneath the feeding fingers issmooth and highly polished. It has been the practice in the art to make the entire surface of the coverplate smooth for'this purpose, however, such construction reduces the effectiveness of the presser member 22 which serves to clamp the fabric in place during the nonfeeding intervals of the stitching cycle. If the fabric slips between the presser member and the cover-plate as, for instance, duringpenetration and withdrawal of the needle, the loosened fabric will permit flagging to occur, that is, the loose fabric will be carried upwardly and downwardly with the needle, resulting in the possible skipping of stitches or the crratic and imperfect formation of some of the stitches. Equally objectionable is flagging of the loose fabric under the action of the piercer 24. The action of both the needle and the piercer is to stretch a hole in the fabric, and such stretching, which is more pronounced under the action of the piercer because of its larger. diameter, gives rise to considerable friction therebetween. If the fabrics are not clamped securely, they will be carried with the piercer which will then produce a raggededged imperfect hole in the fabrics rather'than the desired clean-edged variety. 3

In order to eliminate slippage of the fabrics beneath the presser member 22, the surface of the cloth plate in this vicinity has been roughened in a particularly eifective manner. The extent of the roughened area, as indicated at 50 in Fig. 2, is preferably at least coextensive with the vertically projected outline of the presser member 2 2, of the hemstitch' attachment. The remainder of the cover plate surface may remain smooth so as to preserve the a completely random fashion so as not to favor slippage of the fabric in any direction. While it is important that the area 50 be roughened, it is desirable that the roughness be not excessive otherwise the normal advance of the work by the attachment feed will not be uniform. In other words, it is important that the degree of roughness be such as to eliminate inadvertent slip of the fabric yet will permit uniform feeding of the fabric past the stitching instrumentalities; A surface 50 provided as a result of sandblastinghas been found to be particularly well suited for this purpose.

Having thus set forth the nature of the invention, what I claim herein is:

1. A feed cover-plate for a sewing machine having a frame provided with a pair of tapped attachment fastener securing holes, said feed cover-plate being formed with an arm having opposite sides of which one side is adapted to abut said sewing machine frame, a pair of fastening screws each having a-threaded shank formed with a narrowed. neck portion, -said feed cover-plate arm being formed with an'elongate aperture, said elongate aperture having a width slightly larger than the'diameter of the threaded portions of said fastening screws, said fastening' screws each being disposed for axial movement through said elongate aperture, a fastening screw retainer secured to said feed cover-plate arm at a pointremote from said elongate aperture therein and at the side of said arm opposite that which is adaptedto abut said sewing machine frame, and a pairof .separateresilient members carried by said fastening screw retainer, each of said resilient members being bifurcated and formed with a keyhole shaped spacebetween bifurcations, of which keyhole shaped space the narrowest portion has a width less than the diameter of the necked portion of said fastening. means and ,the widest portion hasa width less than the diameter of the threadedshank and greater than the. diameter of said necked portion of said fastening screws. each toembrace the .necked portion of one of said fastening screws ,over the elongate aperture of said feed cover plate arm. l v

2-. A devicefor fastening an attachment formed with .anaperture to a'sewing machine having a tapped hole -formed;t-herein, comprising a fastening screw having a threaded shank of sufficient size and shape in cross sectionaldimensions to be accommodated insaid attachment aperture with slight glearance on all sides, said threaded shankl being disposed for axial movement through said attachment aperture, a narrowed neck portion. formed on said threaded shank, a resilient member formed with an open ended keyhole shaped slot disposed to embrace the narrowed neck portion ofsaid fastening screw, said keyhole shaped slothaving at the widest portion a width less than the diameter of. said threaded shank andat the narrowest portion a width less' than the narrowed; neck portion of said threaded shank, saidre- .silienfmember beingdeformable to open the narrowest portion of said keyhole'shaped .slot for passage of the narrowed neck portion of said fastening" screw into the widest portion of said keyhole shaped slot, and means for securing said resilient 'inember' to saida'ttachment at a point remote, from said aperturewith the widest portachment' aperture. v

3. A device for fastening an attachment formed with an elongate'aperture 'to a sewing machine'frame'having a'pair of. tapped holesformed therein,'comprising a pair of'fa'stening screws each having a' threaded shank with a diameter smaller than the width'of said attachment aperture, ,the threaded shanks of said fastening screws each. being disposed for axial movement through the ,tion of said keyhole shaped slot disposed over said atelongate aperture of said attachment, a narrowed neck portion formed onthe threaded shank of each of said fas'tening sc'rews, a fastening screw retainer, "means for separate resilient members carried by' said fastening screw retainer, each of said resilient members having bifurcated portions defining therein open ended keyhole shaped slots, said bifurcated portions being deformable to widen the keyhole shaped slots for insertion of a fastening screw from the open end thereof and dimensioned in the undeformed state each to embrace the necked portion of one of said fastening screws above the elongate aperture of said attachment.

421,978 Sohwalbach Feb. 25, v 1890 Grifiith ct a1. -1" Apr. 22, 1924 Hinman Feb. 2, 1937 Comfer Feb. 13, 1945 Enos Apr. 22, 1952 Enos Mar. 17, 1959 FOREIGN PATENTS Switzerland May 17, 1901 Switzerland June 16, 1923 

